KR20100008579A - Patterns having super-hydrophobic and super-hydrorepellent surface and method of forming the same - Google Patents

Abstract

PURPOSE: A pattern with super hydrophobic and super hydrorepellent surfaces and a method for forming the same are provided to implement super hydrophobic and super hydrorepellent surfaces on various substrates using a microlens array or micro bowl array. CONSTITUTION: A microbowl array(200) is comprised of a plurality of micro bowls. The depth of the micro bowl is 0.5 um to 100 um. The diameter of the micro bowl is 1 to 50 um. The diameter of the micro bowl is equal to or larger than the intervals between the micro bowls. An aspect ratio of the micro bowl is 0.5 to 10. A nano structure or micro nano composite(203) is formed on the surface of the micro bowl. The nano structure or micro-nano composite increases the surface roughness of the micro bowl.

Description

PATTERNS HAVING SUPER-HYDROPHOBIC AND SUPER-HYDROREPELLENT SURFACE AND METHOD OF FORMING THE SAME}

The present invention relates to a pattern having a superhydrophobic and superhydrophobic surface and a method of forming the same.

In general, the method of implementing a hydrophobic surface can be largely divided into structural methods and chemical methods.

First, a structural method of implementing a hydrophobic surface is known to increase the roughness of the material surface to increase the contact angle between the solid material surface and the liquid. Many techniques have been reported for implementing superhydrophobic surfaces using a property in which hydrophobicity increases as the material surface becomes rough.

However, the prior art is mostly concentrated in patterns of hydrophobic surfaces having a columnar structure. The manufacturing method of the pattern of the hydrophobic surface is complicated, and in terms of material, it is expensive for the production material. In addition, there is a limit to uniformly forming on a large area substrate, there is a problem that can not be formed on a flexible substrate (flexible).

Next, a chemical method of implementing a hydrophobic surface is a method of coating a hydrophobic chemical such as fluorocarbon or hydrocarbon on the surface of the material. Among hydrophobic chemicals, fluorocarbon polymers are widely used because they are known to exhibit strong hydrophobicity. Meanwhile, a method of realizing a surface in which hydrophilicity and hydrophobicity are reversible using a property of changing a chemical composition of a specific material by light or heat has also been proposed.

However, in the case of the chemical method for implementing the hydrophobic surface, there is a disadvantage that the material that can be used for the implementation of the hydrophobic surface is limited.

An object of the present invention for solving this problem is to provide a uniformly formed pattern having a superhydrophobic and superhydrophobic surface.

It is also an object of the present invention to provide a method capable of embodying a pattern having superhydrophobic and superhydrophobic surfaces on various substrates of a large area using various materials.

The pattern having a superhydrophobic and superhydrophobic surface according to the present invention includes a microbowl array in which a plurality of micro bowls having a diameter of 1 μm to 50 μm and a depth of 0.5 μm to 100 μm are uniformly arranged.

It is preferable to further include a nanostructure or micro-nanocomposite formed on the surface of the microphone bowl.

It is preferable that the aspect ratio which shows the ratio of the diameter and depth of a micro bowl has a range of 0.5 or more and 10 or less.

The diameter of the microbowl is preferably equal to or longer than the spacing of the microbowl, which is the center distance between adjacent microbowl.

It is preferable that the diameter of the micro bowl is longer than the spacing of the micro bowl so that there is no flat surface between the plurality of micro bowls.

The aspect ratio representing the ratio of the diameter and depth of the micro bowl is in the range of 0.5 to 10, but the diameter of the micro bowl is flat between the plurality of micro bowls because the diameter of the micro bowl is longer than the distance between the micro bowls, which is the center distance between adjacent micro bowls. It is preferable that it is formed so that there is no surface.

The pattern having a superhydrophobic and superhydrophobic surface according to the present invention includes a microlens array in which a plurality of microlenses having a diameter of 1 μm to 50 μm and a height of 0.5 μm to 100 μm are uniformly arranged.

It is preferable to further include a nanostructure or micro-nanocomposite formed on the surface of the microlens.

It is preferable that the aspect ratio which shows the ratio of the diameter and height of a micro lens has a range of 0.5 or more and 10 or less.

The diameter of the microlenses is preferably equal to or longer than the spacing of the microlenses, which is the center distance between the microlenses adjacent to each other.

It is preferable that the diameter of the microlenses has a length longer than that of the microlenses so that there is no flat surface between the plurality of microlenses.

The aspect ratio representing the ratio of the diameter and the height of the microlenses may be in a range of 0.5 to 10, but the diameter of the microlenses is longer than the interval of the microlenses, so that the microlenses are formed so that there is no flat surface between the plurality of microlenses. .

The method for forming a pattern having a superhydrophobic and superhydrophobic surface according to the present invention comprises the steps of (a) forming a microlens array in which a plurality of microlenses are uniformly arranged using a photolithography process and (b) microlenses Using the array as a frame to form a micro bowl array in which a plurality of micro bowls having complementary shapes of micro lenses are uniformly arranged.

after step (b),

It is preferable to further include forming a nanostructure or a micro-nanocomposite on the surface of the micro bowl by etching the surface of the micro bowl through a plasma etching or an ion milling etching process so as to increase the surface roughness of the micro bowl array. .

after step (b),

It is preferable to further include the step of surface modification by coating a hydrophobic material on the microbowl surface.

The method for forming a pattern having a superhydrophobic and superhydrophobic surface according to the present invention comprises the steps of (a) forming a micro bowl array using a photolithography process and (b) complementing the micro bowl using the micro bowl array as a frame. Preferably, the method includes forming a microlens array in which a plurality of microlenses having a proper shape are uniformly arranged.

after step (b),

The method may further include forming nanostructures or micro-nanocomposites on the surface of the microbowl by etching the surface of the microlens through plasma etching or etching of ion milling to increase the roughness of the surface of the microlens array. Do.

after step (b),

The method may further include coating and modifying the surface of the hydrophobic material on the plurality of microlens surfaces.

According to the present invention, a method of forming a pattern having a superhydrophobic and superhydrophobic surface comprises: (a) patterning a masking material on a substrate, and isotropically etching one surface of the substrate through the patterned masking material, thereby forming a plurality of micro bowls. To form a uniformly arranged micro bowl array And (b) forming a microlens array in which a plurality of microlenses having a complementary shape of the microbowl are uniformly arranged using the microbowl array as a frame.

after step (b),

The method may further include forming nanostructures or micro-nanocomposites on the surface of the microbowl by etching the surface of the microlens through plasma etching or etching of ion milling to increase the roughness of the surface of the microlens array. Do.

after step (b),

It is preferable to further include the step of surface modification by coating a hydrophobic material on the microlens surface.

According to the present invention, it is possible to implement a superhydrophobic and superhydrophobic surface by using the structure of the microlens array and the micro bowl array.

In addition, various materials may be used to implement superhydrophobic and superhydrophobic surfaces on a variety of substrates, from non-flexible substrates to flexible substrates, and the degree of superhydrophobicity and superhydrophobicity may be controlled by adjusting aspect ratios of the microlenses and the micro bowl.

Hereinafter, a pattern having a superhydrophobic and superhydrophobic surface according to a first embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a micro bowl array having a superhydrophobic and superhydrophobic surface according to a first embodiment of the present invention.

Referring to FIG. 1, a pattern having a superhydrophobic and superhydrophobic surface according to the present invention includes a micro bowl array 200 in which a plurality of micro bowls are uniformly arranged. Microbowl refers to a concave pattern having a predetermined diameter d1 and depth h1, as shown in FIG. The microbowl has a diameter (d1) of 1 μm to 50 μm and a depth (h1) of 0.5 μm to 100 μm, but the aspect ratio (h1 / d1) representing the ratio of the diameter (d1) and the depth (h1) of the microbowl is It is preferable that it is formed to have a range of 0.5 or more and 10 or less. In addition, the diameter d1 of the microbowl may be formed to have a length equal to or longer than the spacing p1 of the microbowl, which is a center distance between adjacent microbowl. Here, the diameter d1 and the spacing p1 of the micro bowl will be described with reference to the drawing shown in FIG. 30. 30 is a view showing the upper side of the micro bowl array. In FIG. 30A, one circle represents one micro bowl, and the length d of the straight line passing through the center of the circle represents the diameter d1 of the micro bowl, and the length of the straight line connecting the centers between adjacent micro bowls ( p) represents the interval p1 of the microbowl. Here, FIG. 30A illustrates a case in which the diameter d1 of the micro bowl is equal to the interval p1 of the micro bowl.

In addition, the plurality of micro bowls may be formed such that the diameter d1 is longer than the spacing p1 of the micro bowls so that there is no flat surface between the micro bowls. Here, as shown in Fig. 30B, the diameter d1 of the microbowl is defined as a length d of a straight line passing through the center of the imaginary circle representing the microbowl when it is formed to overlap at least partially between adjacent microbows. Correspondingly, the spacing p1 of the micro bowl corresponds to the length p of a straight line connecting the centers between adjacent circles. In addition, the flat surface refers to a surface configured flat when the depth of the micro bowl is 0, and when a plurality of micro bowls are formed as shown in Figure 30b, the overlapping points (Pk) between the micro bowls each have a peak structure Will be achieved.

The surface of the micro bowl array 200 shown in FIG. 1 forms a contact angle upon contact with a liquid. The contact angle is a measure of the hydrophobicity or water repellency of the material surface. As the value increases, the hydrophobicity and water repellency of the material surface increases. The contact angle of the surface of the micro bowl array 200 increases as the aspect ratio h1 / d1 of the micro bowl increases. In addition, the contact angle may be greater when the diameter (d1) of the micro bowl is formed to be equal to or longer than the distance (p1) of the micro bowl, compared to the case where the diameter (d1) of the micro bowl is shorter than the interval (p1) of the micro bowl. Can be. This is because the point where the micro bowl meets the micro bowl has a peak structure without a flat surface from the moment when the diameter d1 of the micro bowl is longer than the micro bowl interval p1. Hydrophobicity and water repellency of the micro bowl (h1 / d1) starts to appear from 0.5 or more, and if increased to 10, the contact angle is increased to about 179 degrees to maximize the hydrophobicity and water repellency of the surface of the micro bowl array (200) Will be. 27 is an electron micrograph showing a micro bowl array according to the present invention.

2 is a cross-sectional view of the micro bowl array 200 in which a nanostructure or micro-nano composite 203 is formed on the surface of the micro bowl.

Nanostructures or micro-nanocomposites 203 formed on the surface of the microbowl serve to further increase hydrophobicity and water repellency by increasing the surface roughness of the microbowl array 200. As a result, hydrophobicity and water repellency may also appear on the surface of the micro bowl array 200 having an aspect ratio h1 / d1 of 0.5 or less. The nanostructure or micro-nanocomposite 203 may be formed by partially etching the surface of the micro bowl array 200, and nanowires such as carbon nanotubes or ZnO, BN, GaN, CoSi, CrSi, FeSi, InP, or the like. The nanostructure 203 such as (nanowire) or nanodot (nanodot) may be formed by immobilizing on the surface of the micro bowl array 200.

In addition, when a hydrophobic chemical such as fluorocarbon or hydrocarbon is coated on the surface of the micro bowl array 200, even if the aspect ratio h1 / d1 of the micro bowl is 0.5 or less, the surface of the micro bowl array 200 may be hydrophobic. And water repellency.

Hereinafter, a pattern having a superhydrophobic and superhydrophobic surface according to a second embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view of a microlens array having a superhydrophobic and superhydrophobic surface according to a second embodiment of the present invention.

Referring to FIG. 3, the pattern having the superhydrophobic and superhydrophobic surface according to the present invention includes a microlens array 400 in which a plurality of microlenses are uniformly arranged. As shown in FIG. 3, the microlens may refer to a convex pattern having a predetermined diameter d2, a gap p2, and a height h2, and may also be complementary to the microbowl described through the first embodiment. It can mean a pattern having a conventional structure. The microlenses have a diameter (d2) of 1 µm to 50 µm and a height (h2) of 0.5 µm to 100 µm, but the aspect ratio (h2 / d2) representing the ratio of the diameter (d2) and the height (h2) is 0.5 or more. It is preferable that it is formed to have a range of 10 or less. In addition, the microlens may have a diameter d2 of the microlens having a length equal to the interval p2 of the microlens. In addition, the diameter d2 of the microlenses may be formed to have a length equal to or longer than the spacing p2 of the microlenses, which is a center distance between the microlenses adjacent to each other. Here, the diameter d2 and the interval p2 of the microlens will be described with reference to the drawing shown in FIG. 30. 30 is a view showing an image side surface of a microlens array. In FIG. 30A, one circle represents one microlens, and the length d of the straight line passing through the center of the circle represents the diameter d2 of the microlens, and the length of the straight line connecting the centers between adjacent microlenses ( p) represents the interval p2 of the microlenses. Here, FIG. 30A is a diagram illustrating a case where the diameter d2 of the microlens is equal to the interval p2 of the microlens.

In addition, the plurality of microlenses may be formed such that the diameter d2 is longer than the interval p2 of the microlenses so that there is no flat surface between the microlenses. Here, when the diameter d2 of the microlens is formed to overlap a part of adjacent microlenses, as shown in FIG. 30B, the diameter d2 of the microlens is equal to the length d of the straight line passing through the center of the virtual circle representing the microlens. Correspondingly, the spacing p2 of the microlenses corresponds to the length p of a straight line connecting the centers between adjacent circles. In addition, the flat surface refers to a surface configured flat when the height of the microlens is zero. Among the overlapping portions between the microlenses shown in FIG. 30B, the point Pk corresponds to a portion in which the shape of the shape complementary to the peak structure appears in the case of the micro bowl described above.

The surface of the microlens array 400 shown in FIG. 3 forms a contact angle upon contact with liquid. The contact angle is a measure of the hydrophobicity or water repellency of the material surface. As the value increases, the hydrophobicity and water repellency of the material surface also increase. The contact angle of the surface of the microlens array 400 increases as the aspect ratio h2 / d2 of the microlens increases. In addition, the contact angle may be larger when the diameter d2 of the microlens is equal to the distance p2 of the microlens, as compared with the case where the diameter d2 of the microlens is shorter than the interval p2 of the microlens.

When the aspect ratio (h2 / d2) of the microlenses starts to be 0.5 or more, hydrophobicity and water repellency begin to appear, and when it is increased to 10, the contact angle is increased to about 179 degrees to maximize the hydrophobicity and water repellency of the surface of the microlens array 400. Will be. 28 is an electron micrograph showing a microlens array according to the present invention.

4 is a cross-sectional view of a microlens array 400 in which a nanostructure or nanocomposite 403 is formed on a surface of a microlens.

The nanostructure or micro-nanocomposite 403 formed on the surface of the microlenses increases the surface roughness of the microlens array 400, thereby increasing the hydrophobicity and water repellency of the surface of the microlens array 400. Accordingly, even if the aspect ratio h2 / d2 of the microlens is 0.5 or less, hydrophobicity and water repellency may appear on the surface of the microlens array 400. Nanostructure or micro-nanocomposite 403 may be formed by partially etching the surface of the microlens array 400, nanowires such as carbon nanotubes or ZnO, BN, GaN, CoSi, CrSi, FeSi, InP It may be formed by fixing a nanostructure 403, such as (nanowire) or nanodot (nanodot) on the surface of the microlens array (400).

FIG. 29 is an electron micrograph showing a PDMS (polydimethylsiloxane) microlens array having nanostructures formed thereon. FIG. 29 illustrates a PDMS microlens array physically etched for about 4 minutes under conditions of 500 W plasma power and 100 sccm CF4 gas flow rate.

In addition, when a hydrophobic chemical such as fluorocarbon or hydrocarbon is coated on the surface of the microlens array 400, even if the aspect ratio (h2 / d2) of the microlens is about 0.5 or less, the surface of the microlens array 400 may be hydrophobic. And water repellency.

Hereinafter, a method of forming a pattern having a superhydrophobic and superhydrophobic surface according to a preferred embodiment of the present invention will be described.

First, a method of forming a micro bowl array will be described.

5 to 8 illustrate a method of forming a micro bowl array.

The method of forming a micro bowl array according to the present invention may include 1) forming a microlens array using a photolithography process, and 2) forming a micro bowl array using the microlens array as a frame. In addition, the method may further include 3) forming a nanostructure or micro-nanocomposite and 4) coating a hydrophobic material to increase the hydrophobicity and water repellency of the micro bowl array surface.

1) forming a microlens array.

First, as shown in FIG. 5, the negative photosensitive photoresist 210 is formed on one surface of the substrate 110, and has a constant distance 10d from the glass substrate 13 on the other surface of the substrate 110. The photomask 10 and the diffuser 20 constituted by the mask pattern 11 are sequentially arranged. Thereafter, light propagating in a parallel direction is radiated to the diffuser 20. Light traveling in a parallel direction is scattered through the diffuser 20 so that the light can travel in an arbitrary direction. The light scattered through the diffuser 20 exposes the negative photosensitive photoresist 210 through the photomask 10 and the substrate 110. Accordingly, as shown in FIG. 5, the exposure region 211a in the form of a micro lens is formed in the negative photosensitive photoresist 210.

Thereafter, the exposed negative photosensitive photoresist 210 is removed to remove the unexposed regions through the development process. Accordingly, as shown in FIG. 6, a microlens array 211b in which a plurality of microlenses is uniformly arranged is formed. As illustrated in FIG. 6, the microlens has a predetermined diameter d2, a height h2, and a gap p2, and refers to a pattern that is convex in the vertical direction with respect to one surface of the substrate 110. Here, the interval p2 of the microlens array 211b means the center distance of the microlens array 211b adjacent to each other. The microlens array 211b shown in FIG. 6 may be used as it is as a pattern having hydrophobicity and water repellency, and may be used to form a micro bowl array.

2) forming a micro bowl array.

FIG. 7 illustrates a method of forming the micro bowl array 220 using the micro lens array 211b as a frame.

As shown in FIG. 7, when various polymer materials such as PDMS, polyimide, and Teflon are poured into a structure using the microlens array 211b as a frame, the microlens array It is possible to form a micro bowl array 220 having a complementary form of 211b). In addition, the micro bowl array 220 may be formed by depositing or plating a metal material such as gold, nickel, or copper using the microlens array 211b as a mold. When the adhesion between the constituent material of the microlens array 211b and the constituent material of the micro bowl array 220 is good, as shown in FIG. 7, when the anti-stick layer 230 is coated, the micro bowl After the array 220 is formed, separation can be easily performed.

FIG. 8 illustrates a microbowl array 220 formed through the method shown in FIG. 7.

The diameter d1 of the microbowl shown in FIG. 8 is formed in the range of 1 μm to 50 μm, and the depth h1 is formed in the range of 0.5 μm to 100 μm, and the diameter of the microbowl d1 and The aspect ratio h1 / d1 representing the ratio of the depth h1 is to be formed within a range of 0.5 or more and 10 or less.

The surface of the micro bowl array 220 forms a contact angle upon contact with the liquid. The contact angle is a measure of the hydrophobicity or water repellency of the material surface. As the value increases, the hydrophobicity and water repellency increases. In the case of the micro bowl array 220, the contact angle increases as the aspect ratio (h1 / d1) of the micro bowl increases. . On the surface of the micro bowl array 220, the hydrophobicity and water repellency begin to appear from 0.5 or more in the aspect ratio (h1 / d1) of the micro bowl, and when it is increased to 10, the contact angle increases to about 179 degrees, thereby increasing the hydrophobicity and water repellency of the surface. You get the best.

The contact angle may be adjusted according to the aspect ratio h1 / d1 of the micro bowl, and the aspect ratio h1 / d1 of the micro bowl may be adjusted according to the aspect ratio h2 / d2 of the microlens. Therefore, by adjusting the aspect ratio (h1 / d1) of the micro bowl according to the interval 10d between the patterns of the photomask 10, the exposure time or the exposure energy in the photolithography process for forming the microlens array 211b, Hydrophobicity and water repellency of the bowl array 220 can be adjusted.

3) forming nanostructures and micro-nanocomposites.

As shown in FIG. 9, the nanostructure or the micro-nanocomposite 221 may be formed on the surface of the micro bowl so that the surface roughness of the micro bowl array 220 is increased. The nanostructure or micro-nanocomposite 221 may be formed by etching the surface of the microbowl using an etching method suitable for an etched material such as plasma etching or ion milling. Some may also be formed by being fixed on the microbowl again. In addition, the nanostructure or the micro-nanocomposite 221 is a carbon nanotube or a nanowire or nanodot (ZnO, BN, GaN, CoSi, CrSi, FeSi, InP, etc.) on the surface of the micro bowl. The structure may be formed by immobilization.

4) coating the hydrophobic material

As shown in FIG. 10, the hydrophobic material 223 may be coated on the surface of the micro bowl array 220 to increase hydrophobicity and water repellency. When the hydrophobic material 223 is coated, the surface energy of the microbowl array 220 is reduced to further increase hydrophobicity and water repellency. The hydrophobic material 223 coated on the surface of the micro bowl array 220 may include fluorocarbon or hydrocarbon.

11 to 14 illustrate another method of forming a micro bowl array according to an embodiment of the present invention.

A second method of forming a micro bowl array according to the present invention includes the steps of 1) forming a micro bowl array using an isotropic etching process. In addition, the method may further include 2) forming a nanostructure or a micro-nanocomposite and 3) coating a hydrophobic material to increase the hydrophobicity and water repellency of the micro bowl array surface.

1) forming a micro bowl array.

First, as shown in FIG. 11, the masking material 130 is patterned on the substrate 120 to define a region where a subsequent micro bowl array is to be formed. As the substrate 120 illustrated in FIG. 11, any material capable of wet etching may be used.

Thereafter, one surface of the substrate 120 is isotropically etched through the patterned masking material 130, and as illustrated in FIG. 12A or 12B, the micro bowl array 121 in which a plurality of micro bowls are uniformly arranged. ).

The microbowl shown in FIGS. 12A and 12B means a pattern having a predetermined diameter d, a gap p, and a depth h, and formed concave. Here, the spacing p of the micro bowl means a center distance between the micro bowls adjacent to each other. The diameter (d) of the micro bowl is formed in the range of 1 μm to 50 μm, the depth (h) is formed in the range of 0.5 μm to 100 μm, and the diameter (d) and depth (h) of the micro bowl Aspect ratio (h / d) which shows a ratio is formed so that it may have a range of 0.5 or more and 10 or less.

The surface of the micro bowl array 121 forms a contact angle upon contact with the liquid. The contact angle is a measure of the hydrophobicity or water repellency of the surface of the material. As the value increases, the hydrophobicity and water repellency increases. In the case of the micro bowl array 121, the contact angle increases as the aspect ratio (h / d) of the micro bowl increases. . On the surface of the micro bowl array 121, the aspect ratio (h / d) of the micro bowl begins to show hydrophobicity and water repellency from 0.5 or more, and when it is increased to 10, the contact angle increases to about 179 degrees, thereby increasing the hydrophobicity and water repellency of the surface. You get the best.

The contact angle can be adjusted according to the aspect ratio (h / d) of the microbowl. Accordingly, as shown in FIGS. 12A and 12B, the micro bowl array 121 is adjusted by adjusting the aspect ratio h / d of the micro bowl according to the etching time and the interval 130d between the masking materials 130 during the isotropic etching process. ) Can control the degree of hydrophobicity and water repellency.

As an example of a method of forming a micro bowl array, a photomask is formed by patterning a photoresist on a glass substrate using a photolithography method, and then using HF, a glass micro bowl array is formed by isotropic wet etching. can do.

2) forming nanostructures or micro-nanocomposites.

As shown in FIG. 13, the nanostructure or the micro-nanocomposite 123 may be formed on the surface of the micro bowl so that the surface roughness of the micro bowl array 121 is increased.

The nanostructure or micro-nanocomposite 123 may be formed by etching the surface of the microbowl using an etching method suitable for an etched material such as plasma etching or ion milling. Some may also be formed by being fixed on the microbowl again. In addition, the nanostructure or the micro-nanocomposite 123 is a carbon nanotube or a nanowire or nanodot (ZnO, BN, GaN, CoSi, CrSi, FeSi, InP, etc.) on the surface of the micro bowl. The structure may be formed by immobilization.

3) coating the hydrophobic material.

As shown in FIG. 14, the hydrophobic material 125 may be coated on the surface of the micro bowl array 121 to increase hydrophobicity and water repellency. When the hydrophobic material 125 is coated, the surface energy of the micro bowl array 121 is reduced to further increase hydrophobicity and water repellency. The hydrophobic material 125 coated on the surface of the micro bowl array 121 may include fluorocarbon or hydrocarbon.

Next, a method of forming the microlens array will be described.

15 to 20 illustrate a first method of forming a microlens array according to an embodiment of the present invention.

The method of forming a microlens array according to the present invention may include 1) forming a micro bowl array using a photolithography process, and 2) forming a micro lens array using the micro bowl array as a frame. In addition, the method may further include 3) forming a nanostructure or micro-nanocomposite and 4) coating a hydrophobic material to increase the hydrophobicity and water repellency of the microlens array surface.

1) forming a micro bowl array.

First, as shown in FIG. 15, a positive photosensitive photoresist 410a is formed on the substrate 301, and a mask having a predetermined distance 10d from the glass substrate 13 on the positive photosensitive photoresist 410a. The photomask 10 and the diffuser 20 formed of the pattern 11 are sequentially arranged. Thereafter, light propagating in a parallel direction is radiated to the diffuser 20. Light traveling in a parallel direction is scattered through the diffuser 20 so that the light can travel in an arbitrary direction. Light scattered through the diffuser 20 exposes the positive photosensitive photoresist 410a through the photomask 10. Accordingly, as shown in FIG. 15 As described above, the exposure region 411 is formed in the positive photosensitive photoresist 410a in the form of a micro bowl array.

Thereafter, the exposure area 411 is removed through the development process. Accordingly, as shown in FIG. 16, the micro bowl array 410 b is formed in which a plurality of micro bowls are uniformly arranged. The micro bowl means a pattern formed concavely having a predetermined diameter d1, a gap p1, and a height h1. Here, the interval p1 of the micro bowl means the center distance between the micro bowls adjacent to each other. The micro bowl array 410 b shown in FIG. 16 can be used as it is as a surface having hydrophobicity and water repellency, and can be used to form a micro lens array.

27 is an electron micrograph showing a photoresist micro bowl array formed using a photoresist.

2) forming a microlens array.

FIG. 17 illustrates a method for forming the microlens array 420 using the micro bowl array 410b as a frame.

As shown in FIG. 17, when various polymer materials such as PDMS (polydimethylsiloxane), polyimide, and Teflon are poured into a structure using the micro bowl array 410b, the micro bowl array (410b) is used. It is possible to form a microlens array 420 having a complementary form of 410b. In addition, the microlens array 420 may be formed by depositing or plating a metal material such as gold, nickel, or copper using the micro bowl array 410b as a frame. When adhesion between the constituent material of the micro bowl array 410b and the constituent material of the microlens array 420 is good, as shown in FIG. 17, when the anti-stick layer 430 is coated, the microlens array 420 is formed. Separation can be performed easily. When the microlens array 420 is formed on a substrate, the microlens array 420 may be formed on a variety of substrates from non-flexible substrates to flexible substrates as surfaces having superhydrophobicity and superhydrophobicity.

18 illustrates a microlens array 420 formed through the method illustrated in FIG. 17.

The diameter d2 of the microlens shown in FIG. 18 is formed in the range of 1 μm to 50 μm, and the height h2 is formed in the range of 0.5 μm to 100 μm, and the diameter d2 of the microlens is The aspect ratio h2 / d2 representing the ratio of the height h2 is formed to have a range of 0.5 or more and 10 or less.

The surface of the microlens array 420 forms a contact angle upon contact with the liquid. The contact angle is a measure of the hydrophobicity or water repellency of the surface of the material. As the value increases, the hydrophobicity and water repellency increases. In the case of the microlens array 420, the contact angle increases as the aspect ratio (h2 / d2) of the microlenses increases. . On the surface of the microlens array 420, the aspect ratio (h2 / d2) of the microlens starts to show hydrophobicity and water repellency from 0.5 or more, and when it is increased to 10, the contact angle increases to about 179 degrees so that the hydrophobicity and water repellency of the surface is increased. You get the best.

The contact angle may be adjusted according to the aspect ratio h2 / d2 of the microlens, and the aspect ratio h2 / d2 of the microlens may be adjusted according to the aspect ratio h1 / d1 of the micro bowl used as a frame. Therefore, in the photolithography process, the hydrophobicity and water repellency of the microlens array 420 are adjusted by adjusting the aspect ratio h2 / d2 of the microlens according to the interval 10d between the patterns of the photomask 10, the exposure time, or the exposure energy. Can be adjusted.

FIG. 28 is an electron micrograph of a PDMS microlens array formed by pouring and curing PDMS (polydimethylsiloxane), which is a type of polymer, using the photoresist micro bowl array of FIG. 27 as a frame.

3) forming nanostructures and micro-nanocomposites.

As shown in FIG. 19, the nanostructure or the micro-nanocomposite 421 may be formed on the surface of the microlens such that the surface roughness of the microlens array 420 is increased. The nanostructure or micro-nanocomplex 421 may be formed by partially etching the surface of the microlens using an etching method suitable for an etched material such as plasma etching or ion milling. The etched portion may be formed by being fixed on the microlens again. In addition, the nanostructure or the micro-nanocomposite 421 is a carbon nanotube or nanowire or nanodot such as ZnO, BN, GaN, CoSi, CrSi, FeSi, InP or the like on the surface of the microlens. The structure may be formed by immobilization.

FIG. 29 is an electron micrograph showing a PDMS microlens array in which nanostructures are formed through physical etching of the surface of the PDMS microlens array shown in FIG. 28.

4) coating the hydrophobic material.

As shown in FIG. 20, the hydrophobic material 423 may be coated on the surface of the microlens array 420 to increase hydrophobicity and water repellency. When the hydrophobic material 423 is coated, the surface energy of the microlens array 420 is reduced to further increase hydrophobicity and water repellency. The hydrophobic material 423 coated on the surface of the microlens array 420 may include fluorocarbon or hydrocarbon.

21 to 26 are diagrams illustrating a second method of forming a microlens array according to an embodiment of the present invention.

A second method of forming a microlens array according to an embodiment of the present invention includes 1) forming a micro bowl array using isotropic etching and 2) forming a micro lens array using the micro bowl array as a frame. do. In addition, 3) forming a nanostructure or micro-nanocomposite on the surface of the microlens array to increase the hydrophobicity and water repellency of the microlens array surface and 4) coating a hydrophobic material on the surface of the microlens array It includes more.

1) forming a micro bowl array.

21 to 22 illustrate a method of forming the micro bowl array 320 using isotropic etching.

First, as shown in FIG. 21, the masking material 330 is patterned on the substrate 320 to define a region in which the micro bowl array is to be formed. As the substrate 320 illustrated in FIG. 12, all materials capable of wet etching may be used.

Thereafter, one surface of the substrate 320 is isotropically etched through the patterned masking material 330, and as shown in FIGS. 22A and 22B, the micro bowl array 321 having a plurality of micro bowls uniformly arranged. To form.

2) forming a microlens array.

23 to 24 illustrate a method of forming the microlens array 420 using the micro bowl array 320 as a frame.

As shown in FIG. 23, when various polymer materials such as PDMS (polydimethylsiloxane), polyimide, and Teflon are poured into a structure using the micro bowl array 321 as a frame, the micro bowl array ( It is possible to form a microlens array 420 having a complementary shape of 320. In addition, the microlens array 420 may be formed by depositing or plating a metal material such as gold, nickel, or copper using the micro bowl array 320 as a frame. When the adhesion between the constituent material of the micro bowl array 321 and the constituent material of the microlens array 420 is good, as shown in FIG. 23, when the anti-stick layer 430 is coated, the microlens array 420 is formed. Separation can be performed easily. When the microlens array 420 is formed on a substrate, the microlens array 420 may be formed on a variety of substrates from non-flexible substrates to flexible substrates as surfaces having superhydrophobicity and superhydrophobicity.

The diameter d2 of the microlens shown in FIG. 24 is formed in the range of 1 μm to 50 μm, and the height h2 is formed in the range of 0.5 μm to 100 μm, and the diameter d2 of the microlens is The aspect ratio h2 / d2 representing the ratio of the height h2 is formed to have a range of 0.5 or more and 10 or less.

The surface of the microlens array 420 forms a contact angle upon contact with the liquid. The contact angle is a measure of the hydrophobicity or water repellency of the surface of the material. As the value increases, the hydrophobicity and water repellency increases. In the case of the microlens array 420, the contact angle increases as the aspect ratio (h2 / p2) of the microlenses increases. . On the surface of the microlens array 420, the hydrophobicity and water repellency of the microlens begin to appear from 0.5 or more, and when it is increased to 10, the contact angle increases to about 179 degrees, so that the hydrophobicity and water repellency of the surface is increased. You get the best.

The contact angle may be adjusted according to the aspect ratio h2 / d2 of the microlens, and the aspect ratio h2 / d2 of the microlens may be adjusted according to the aspect ratio h1 / d1 of the micro bowl. Accordingly, as shown in FIGS. 22A and 22B, the hydrophobicity and water repellency of the microlens array 420 may be adjusted by adjusting the aspect ratio h2 / d2 of the microlens according to the distance 330d between the masking materials during the isotropic etching process. I can regulate it.

3) forming nanostructures and micro-nanocomposites.

As shown in FIG. 25, the nanostructure or the micro-nanocomposite 421 may be formed on the surface of the microlens such that the surface roughness of the microlens array 420 is increased. The nanostructure or micro-nanocomplex 421 may be formed by etching the surface of the microlens using an etching method suitable for an etched material such as plasma etching or ion milling. Some may be formed by being fixed on the microlens again. In addition, the nanostructure or the micro-nanocomposite 421 is a carbon nanotube or nanowire or nanodot such as ZnO, BN, GaN, CoSi, CrSi, FeSi, InP or the like on the surface of the microlens. The structure may be formed by immobilization.

4) coating the hydrophobic material.

As shown in FIG. 26, the hydrophobic material 423 may be coated on the surface of the microlens array 420 to increase hydrophobicity and water repellency. When the hydrophobic material 423 is coated, the surface energy of the microlens array 420 is reduced to further increase hydrophobicity and water repellency. The hydrophobic material 423 coated on the surface of the microlens array 420 may include fluorocarbon or hydrocarbon.

As described above, those skilled in the art to which the present invention pertains will understand that the present invention may be implemented in other specific forms without changing the technical spirit or essential features. Therefore, the embodiments described above are to be understood in all respects as illustrative and not restrictive, and the scope of the present invention is indicated by the following claims rather than the above description, and the meaning and scope of the claims And all changes or modifications derived from the equivalent concept should be construed as being included in the scope of the present invention.

1 and 2 are cross-sectional views of the microbowl array according to the embodiment of the present invention.

3 and 4 are cross-sectional views of the microlens array according to the embodiment of the present invention.

5 to 14 is a view showing a method of forming a micro bowl array according to the present invention.

15 to 26 illustrate a method of forming a microlens array according to the present invention.

27 is an electron micrograph showing a micro bowl array according to the present invention.

28 is an electron micrograph showing a microlens array according to the present invention.

29 is an electron micrograph showing a microlens array formed with a nanostructure or micro-nano composite according to the present invention.

30 is a view showing an image of the micro bowl array or micro lens array according to the present invention.

******** Explanation of symbols for the main parts of the drawing ********

200: micro bowl array

400: microlens array

203,403: nanostructures or micro-nanocomplexes

Claims (21)

A pattern having a superhydrophobic and superhydrophobic surface, comprising a microbowl array in which a plurality of micro bowls having a diameter of 1 μm to 50 μm and a depth of 0.5 μm to 100 μm are uniformly arranged. The method of claim 1, Further comprising a nanostructure or micro-nanocomposite formed on the surface of the microphone bowl, a pattern having a superhydrophobic and superhydrophobic surface. The method of claim 1, The aspect ratio which shows the ratio of the diameter and depth of the said micro bowl has the range of 0.5 or more and 10 or less, The pattern which has a superhydrophobic and superhydrophobic surface. The method of claim 3, Wherein the diameter of the microbowl has a length equal to or longer than the spacing of the microbows, the center distance between the microbows adjacent to each other. The method of claim 4, wherein And a superhydrophobic and superhydrophobic surface formed such that the diameter of the microbowl is longer than the spacing of the microbowl such that there is no flat surface between the plurality of microbowls. The method of claim 1, The aspect ratio representing the ratio of the diameter and the depth of the micro bowl has a range of 0.5 to 10, wherein the diameter of the micro bowl has a length longer than an interval of the micro bowl which is a center distance between the micro bowls adjacent to each other. A pattern having a superhydrophobic and superhydrophobic surface, formed so that there is no flat surface between the micro bowls. A pattern having a superhydrophobic and superhydrophobic surface comprising a microlens array in which a plurality of microlenses having a diameter of 1 μm to 50 μm and a height of 0.5 μm to 100 μm are uniformly arranged. The method of claim 7, wherein Further comprising a nanostructure or micro-nanocomposite formed on the surface of the microphone lens, a pattern having a superhydrophobic and superhydrophobic surface. The method of claim 7, wherein The aspect ratio which shows the ratio of the diameter and height of the said microlens has a superhydrophobic and superhydrophobic surface which has a range of 0.5 or more and 10 or less. The method of claim 9, Wherein the diameter of the microlenses has a length equal to or longer than the spacing of the microlenses, the center distance between the adjacent microlenses, a superhydrophobic and superhydrophobic surface. The method of claim 10, A pattern having a superhydrophobic and superhydrophobic surface, the diameter of the microlenses being longer than the spacing of the microlenses such that there is no flat surface between the plurality of microlenses. The method of claim 7, wherein The aspect ratio representing the ratio of the diameter and the height of the microlenses is in a range of 0.5 to 10, but the diameter of the microlenses has a length longer than the interval of the microlens so that there is no flat surface between the plurality of microlenses. Patterns having superhydrophobic and superhydrophobic surfaces formed. (a) forming a microlens array in which a plurality of microlenses are uniformly arranged using a photolithography process; And (b) forming a pattern having a superhydrophobic and superhydrophobic surface, using the microlens array as a frame to form a microbowl array in which a plurality of micro bowls having complementary shapes of the microlenses are uniformly arranged; Way. The method of claim 13, After step (b), Etching the surface of the micro-bowl by plasma etching or etching of ion milling to increase the surface roughness of the micro-bowl array to form a nanostructure or micro-nano composite on the surface of the micro-bowl; , Pattern forming method having a superhydrophobic and superhydrophobic surface. The method of claim 13, After step (b), The method of forming a pattern having a superhydrophobic and superhydrophobic surface further comprising the step of surface modification by coating a hydrophobic material on the microbowl surface. (a) forming a microbowl array using a photolithography process; And (b) forming a pattern having a superhydrophobic and superhydrophobic surface, comprising forming a microlens array in which a plurality of microlenses having a complementary shape of the microbow is uniformly arranged using the microbow array as a frame; Way. The method of claim 16, After step (b), Etching the surface of the microlens through a plasma etching or an ion milling etching process to increase the roughness of the surface of the microlens array to form a nanostructure or micro-nanocomposite on the surface of the micro bowl A pattern forming method having a superhydrophobic and superhydrophobic surface. The method of claim 16, After step (b), A method of forming a pattern having a superhydrophobic and superhydrophobic surface further comprising the step of surface modification by coating a hydrophobic material on the plurality of microlens surface. (a) patterning a masking material on a substrate and isotropically etching one surface of the substrate through the patterned masking material to form a micro bowl array in which a plurality of micro bowls are uniformly arranged. step; And (b) forming a microlens array in which a plurality of microlenses having complementary shapes of the microbows are uniformly arranged using the microbow array as a frame, the superhydrophobic and superhydrophobic surface pattern Formation method. The method of claim 19, After step (b), Etching the surface of the microlens through a plasma etching or an ion milling etching process to increase the roughness of the surface of the microlens array to form a nanostructure or micro-nanocomposite on the surface of the micro bowl A pattern forming method having a superhydrophobic and superhydrophobic surface. The method of claim 19, After step (b), And modifying the surface of the microlens by coating a hydrophobic material on the surface of the microlens.

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